53.
The answer is: D
Explanation
The largest size of plants among the following classes is found in option D: Phaeophyceae.
Phaeophyceae, also known as brown algae, are a class of multicellular, photosynthetic marine algae. They are some of the largest and most complex algae, with some species growing up to 60 meters long. Examples of brown algae include kelp and rockweed.
Chlorophyceae, also known as green algae, are a class of freshwater and marine algae that are unicellular, colonial, or multicellular. They can range in size from just a few microns to several centimeters, but they are generally smaller than brown algae.
Bacillariophyceae, also known as diatoms, are a class of unicellular, photosynthetic algae that are found in freshwater and marine environments. They are generally very small, with most species ranging from 2 to 200 microns in size.
Rhodophyceae, also known as red algae, are a class of multicellular, photosynthetic marine algae. They are typically smaller than brown algae, with most species ranging from just a few centimeters to a few meters in size. However, some species of red algae can grow up to 6 meters in length.
Therefore, option D: Phaeophyceae, is the correct answer.
Phaeophyceae, also known as brown algae, are a class of multicellular, photosynthetic marine algae. They are some of the largest and most complex algae, with some species growing up to 60 meters long. Examples of brown algae include kelp and rockweed.
Chlorophyceae, also known as green algae, are a class of freshwater and marine algae that are unicellular, colonial, or multicellular. They can range in size from just a few microns to several centimeters, but they are generally smaller than brown algae.
Bacillariophyceae, also known as diatoms, are a class of unicellular, photosynthetic algae that are found in freshwater and marine environments. They are generally very small, with most species ranging from 2 to 200 microns in size.
Rhodophyceae, also known as red algae, are a class of multicellular, photosynthetic marine algae. They are typically smaller than brown algae, with most species ranging from just a few centimeters to a few meters in size. However, some species of red algae can grow up to 6 meters in length.
Therefore, option D: Phaeophyceae, is the correct answer.